Umbrella



FIG. 1 is a top, front and right side perspective view of an umbrella, showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a rear view thereof; and,

FIG. 7 is a left side view thereof.

The umbrella staff is shown with a symbolic break in length. The appearance of any portion of the article between the break lines forms no part of the claimed design. 

CLAIM The ornamental design for an umbrella, as shown and described. 